+ struct ust_reg_wait_node *wait_node = NULL, *tmp_wait_node;
+ struct ust_reg_wait_queue wait_queue = {
+ .count = 0,
+ };
+
+ health_register(HEALTH_TYPE_APP_REG_DISPATCH);
+
+ health_code_update();
+
+ CDS_INIT_LIST_HEAD(&wait_queue.head);
+
+ DBG("[thread] Dispatch UST command started");
+
+ while (!CMM_LOAD_SHARED(dispatch_thread_exit)) {
+ health_code_update();
+
+ /* Atomically prepare the queue futex */
+ futex_nto1_prepare(&ust_cmd_queue.futex);
+
+ do {
+ struct ust_app *app = NULL;
+ ust_cmd = NULL;
+
+ /*
+ * Make sure we don't have node(s) that have hung up before receiving
+ * the notify socket. This is to clean the list in order to avoid
+ * memory leaks from notify socket that are never seen.
+ */
+ sanitize_wait_queue(&wait_queue);
+
+ health_code_update();
+ /* Dequeue command for registration */
+ node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
+ if (node == NULL) {
+ DBG("Woken up but nothing in the UST command queue");
+ /* Continue thread execution */
+ break;
+ }
+
+ ust_cmd = caa_container_of(node, struct ust_command, node);
+
+ DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
+ " gid:%d sock:%d name:%s (version %d.%d)",
+ ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
+ ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
+ ust_cmd->sock, ust_cmd->reg_msg.name,
+ ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
+
+ if (ust_cmd->reg_msg.type == USTCTL_SOCKET_CMD) {
+ wait_node = zmalloc(sizeof(*wait_node));
+ if (!wait_node) {
+ PERROR("zmalloc wait_node dispatch");
+ ret = close(ust_cmd->sock);
+ if (ret < 0) {
+ PERROR("close ust sock dispatch %d", ust_cmd->sock);
+ }
+ lttng_fd_put(1, LTTNG_FD_APPS);
+ free(ust_cmd);
+ goto error;
+ }
+ CDS_INIT_LIST_HEAD(&wait_node->head);
+
+ /* Create application object if socket is CMD. */
+ wait_node->app = ust_app_create(&ust_cmd->reg_msg,
+ ust_cmd->sock);
+ if (!wait_node->app) {
+ ret = close(ust_cmd->sock);
+ if (ret < 0) {
+ PERROR("close ust sock dispatch %d", ust_cmd->sock);
+ }
+ lttng_fd_put(1, LTTNG_FD_APPS);
+ free(wait_node);
+ free(ust_cmd);
+ continue;
+ }
+ /*
+ * Add application to the wait queue so we can set the notify
+ * socket before putting this object in the global ht.
+ */
+ cds_list_add(&wait_node->head, &wait_queue.head);
+ wait_queue.count++;
+
+ free(ust_cmd);
+ /*
+ * We have to continue here since we don't have the notify
+ * socket and the application MUST be added to the hash table
+ * only at that moment.
+ */
+ continue;
+ } else {
+ /*
+ * Look for the application in the local wait queue and set the
+ * notify socket if found.
+ */
+ cds_list_for_each_entry_safe(wait_node, tmp_wait_node,
+ &wait_queue.head, head) {
+ health_code_update();
+ if (wait_node->app->pid == ust_cmd->reg_msg.pid) {
+ wait_node->app->notify_sock = ust_cmd->sock;
+ cds_list_del(&wait_node->head);
+ wait_queue.count--;
+ app = wait_node->app;
+ free(wait_node);
+ DBG3("UST app notify socket %d is set", ust_cmd->sock);
+ break;
+ }
+ }
+
+ /*
+ * With no application at this stage the received socket is
+ * basically useless so close it before we free the cmd data
+ * structure for good.
+ */
+ if (!app) {
+ ret = close(ust_cmd->sock);
+ if (ret < 0) {
+ PERROR("close ust sock dispatch %d", ust_cmd->sock);
+ }
+ lttng_fd_put(1, LTTNG_FD_APPS);
+ }
+ free(ust_cmd);
+ }